1. Field of the Invention
The present invention relates to an apparatus and method for measuring the properties of fiber pulp, wherein the volume and temperature of a pulp sample are measured, the sample is filtered, by using a pressure difference, in a filtering chamber onto a wire, the air resistance, weight and possibly other properties of the pulp cake thereby formed are measured, the cake is removed from the apparatus, and the devices are washed and calibrated.
2. Description of the Related Art
From Patent Application FI No. 830534 a method and apparatus are known for determining the properties of a fiber pulp of varying consistency without prediluting the fiber pulp. According to the method, the water is first filtered out from the fiber suspension by means of a pressure difference in order to form a pulp cake on a wire, and the pressure difference formed across the pulp cake thereby formed and the volume of air flowing through the cake, i.e. the air resistance of the pulp cake, are measured. The consistency of the fiber suspension is determined by measuring the temperature and air resistance of a fiber suspension batch of predetermined volume and by weighing the pulp cake filtered on the wire. According to Patent Application FI No. 830534, the filtration is carried out using either an endless belt wire, in which case the pulp cake is detached by means of an air nozzle (FIG. 1), or a fixed flat wire, in which case the cake is detached by using a scraper (FIG. 2). In both alternatives the pulp cake is detached from the wire and transferred onto scales for weighing, and this has caused problems, especially at the extremes of the consistency range of the pulp suspension.
In the present invention the above problems have been avoided by weighing the pulp cake together with the wire frame, and at the same time one cleaning step has been eliminated. To achieve this, an apparatus and method for determining the properties of fiber pulp by using a transferrable wire frame, completely different from previous ones, have been developed, and the washing and testing steps of the apparatus can also be incorporated into it.